Effect of Nb-doping and E-poling on dielectric and electric properties of NBT ceramics. (3rd April 2021) - Suchanicz, J.
ABSTRACT: Low-levels of Nb-doped (≤2 at.%) NBT ceramics were synthesized using a conventional ceramic technique. The XRD analysis indicated the formation of a perovskite structure with rhombohedral symmetry where Nb-doping tends to expand the lattice. The dielectric characteristics and piezoelectric coupling are enhanced as a result of microdefect dipole and ferroelectric order disturbance. It was shown that E-poling influences the properties under investigation. This includes a decrease of electric permittivity ( ϵ ) and an increase of depolarization temperature Td and temperature Tm at which ϵ is the maximum. This is accompanied by the increase of tetragonal regions at the cost of rhombohedral phase (visible in the Raman spectra) and redistribution of the microdefect dipoles, hence ferroelectric order.